1. Field
The present disclosure relates generally to mapping applications and, more specifically, to providing dynamic vector map data to display portions of a map in a mapping application.
2. Description of Related Art
Mapping applications have become increasingly popular due to the proliferation of location-aware mobile electronic devices. Typically, a map displayed by a mapping application can be defined by a set of map tiles. These map tiles can either include a raster image, in which the contents of the image are represented by a rectangular grid of colored pixels, or a vector image, in which contents of the image are represented by geometric primitives, such as points, lines, polygons, and the like. For an electronic device to display a desired view of a map, the electronic device can access map tiles corresponding to the viewable area of the map and can render an image based on these map tiles. As users interact with these mapping applications to pan, zoom, or rotate the view of the map, other map tiles can be accessed and used to render updated views.
Conventional mapping systems typically include a set of pre-generated map tiles that can be provided in response to a request from an electronic device. These pre-generated map tiles are typically sized based on the screen size of the electronic device expected to receive the map tiles. For example, the pre-generated map tiles can be sized to prevent the need to use a large number of map tiles to display a portion of a map while avoiding situations in which a large portion of a map tile is located outside the view of the device. While such a system can be used to effectively service requests from most electronic devices, problems can occur when requesting electronic devices have widely varying screen sizes or when a requesting electronic device has a relatively small amount of memory and/or limited bandwidth. For example, a compact mobile electronic device, such as a mobile phone or watch, may have insufficient memory to store large map tiles designed for desktop computers. Additionally, compact mobile electronic devices may lack communication means having a sufficient bandwidth to receive large map tiles at a rate that allows the device to display updates to a map in a timely manner.
Accordingly, there is a need for improved techniques for providing map tiles for mapping applications.